Last year was not an easy year to be a billionaire, Business Insider previously reported. 2018 was the first time in seven years that high net worth individuals saw their fortunes shrink, according to French technology consulting firm Capgemini. Billionaires across the globe lost 7% of their collective net worth in 2018 due to market instability at the end of the year, Wealth-X also found in its 2019 Billionaire Census. Slowing economic growth across the globe and trade tensions also contributed to the wealth drop, according to Wealth-X.

Keep reading to learn more about the people who became billionaires — and those who lost their billionaire status — in 2019.

15 people who became billionaires in 2019 — and 14 who lost their status in the three-comma club slides

15 people who became billionaires in 2019 — and 14 who lost their status in the three-comma club slides

Social media and makeup mogul Kylie Jenner made headlines when she was declared "the world's youngest self-made billionaire" by Forbes in March.

Proactiv founders Katie Ronan and Kathy Fields were also declared billionaires by Forbes in March.

Ronan and Fields, 64 and 61 respectively, met when they were young dermatology residents, fresh out of medical school, according to their website. They may be best known for inventing acne treatment line Proactiv, but it’s their multi-level marketing skincare line Ronan + Fields that made the duo of dermatologists ultrawealthy — Rodan + Fields‘ 300,000 independent consultants have sold $1.5 billion of cosmetics in 2017, Forbes reported in March.

Jeff Greenberg/Universal Images Group via Getty Images

Zoom's stock soared in the video-conferencing company's public trading debut in April, making CEO Eric Yuan a billionaire.

Jay-Z became "hip-hop's first billionaire" in June, according to Forbes.

The rapper has earned millions from sellout tours and chart-topping albums over the course of his nearly 30-year career, Business Insider’s Mark Abadi previously reported. But music is far from his only money-making venture.

Slack founder and CEO Stewart Butterfield was also declared a billionaire in June, after the workplace messaging app's direct listing.

Slack’s market debut may have been what made Butterfield, 46, a billionaire, but it wasn’t the first successful company he founded, Business Insider’s Megan Hernbroth and Rebecca Aydin previously reported. Butterfield also founded photo-sharing site Flickr, which he sold to Yahoo for more than $20 million in 2013.

The launch of a new tech-focused stock market in China minted three billionaires in a single day in July.

Launched on July 22, the STAR market was designed to compete with Nasdaq to trade China’s largest tech companies, Business Insider previously reported. By the end of the first day of trading, the market’s 25 stocks were up an average of 140%, according to CNN Business. The highest performer, semi-conductor part maker Anji Microelectronics Technology, closed up 400%.

SmileDirectClub founders Jordan Katzman and Alex Fenkell became two of the youngest billionaires in the US in September after the company's IPO.

Shares of Katzman’s and Fenkell’s direct-to-consumer dental-product company SmileDirectClub closed down 28% after its first day of trading, but its market cap of $6.4 billion made Katzman and Fenkell — each of whom owns close to a quarter of the company’s class B shares — billionaires.

A 24-year-old Wharton graduate who has posted photos of himself partying with Rihanna and Bella Hadid became a billionaire on October 23, thanks to a generous "gift" from his parents.

Eric Tse now owns 2.7 billion shares, or 21.45%, of Sino Biopharmaceutical, the company founded by his father, the company said in a statement October 23.

The company said Tse’s parents told the board they transferred the shares to Tse to „refine the management and inheritance of family wealth“ and planned for Tse to „hold the relevant shares in long-term.“ But Sino Biopharmaceutical said Tse’s new status would „not have any material impact on the business operations of the Company.“

Tse „indicated that in response to nomination for Billionaire List or wealth ranking organized by media or other organizations, he will endeavor not to participate in such rankings in his own name, and would recommend participating in such nominations in the name of the Tse Ping family,“ Sino Biopharmaceutical said.

REUTERS/Bobby Yip

Oracle co-CEO Safra Catz is one of only a few people to become a billionaire from a company she did not found.

Catz, 57, took over as co-CEO of software developer Oracle after the retirement of fellow billionaire Larry Ellison in 2014, according to Forbes. Catz is now one of the highest-paid women in the world, making $135 million in 2017, Forbes reported.

Business Insider/Julie Bort

Early Uber employee Ryan Graves was added to Forbes' Billionaires List this year.

Graves, 35, was the first employee hired by former Uber CEO Travis Kalanick after responding to a January 2010 tweet from Kalanick asking where Kalanick could find an „entrepreneurial product mgr/biz-dev killer 4 a location based service,“ CNBC reported in May.

Juul cofounders Adam Bowen and James Monsees had short-lived tenures as billionaires.

One of the company’s biggest investors, hedge fund Darsana Capital Partners, reportedly cut the company’s valuation by more than a third on October 3 following increased attention from regulators. As a result, Juul cofounders Adam Bowen and James Monsees lost their billionaire status just ten months after attaining it, Business Insider previously reported.

Bowen and Monsees founded Juul after meeting on smoke breaks while studying product design at Stanford University in 2004, Business Insider previously reported. Ploom, a precursor to Juul, was launched in 2007 and first released Juul products in 2015. The company’s Juul line was spun into a separate firm in 2017. The majority of the pair’s respective net worths are tied to their 1.75% stakes in the e-cigarette maker, Forbes‘ Sergei Klebnikov reported.

Axel Heimken/picture alliance via Getty Images

Forever 21's cofounders lost their billionaire status in July — just three months before the fast-fashion retailer filed for bankruptcy in September.

Net worths: $800 million each

At the company’s peak in 2015, Jin Sook and Do Won Chang had a combined net worth of $5.9 billion, Business Insider previously reported. Their combined fortune has fallen to $1.6 billion as the fast fashion chain enters bankruptcy proceedings. Forever 21 will close 350 stores across the globe, but will continue to operate in select locations and online.

The married couple founded Forever 21 in Los Angeles in 1984 after emigrating from South Korea three years prior. Their first location, originally called Fashion 21, was 900 square feet and stocked merchandise the Changs purchased at wholesale close-out sales, according to Forbes.

The drop in Neumann’s personal net worth from a peak of $4.1 billion was the result of the declining value of Neumann’s 18% stake in WeWork, Forbes reported. WeWork was valued at $47 billion in January following an investment from Japanese investment firm Softbank. However, the company reportedly sought a valuation as low as $10 billion in September as public scrutiny over its steep losses and leadership structure threatened its IPO. Forbes now estimates that the company is worth „at most $2.8 billion.“

O’Leary, 58, has served as the CEO of the cut-rate airline since 1994, according to Forbes. O’Leary once compared RyanAir’s business model to that of Wal-Mart, according to Forbes, saying the airline aims to „pile it high and sell it cheap.“

Four heirs to the Barilla pasta fortune also dropped off Forbes' Billionaires List in March.

Siblings Emanuella, Guido, Luca, and Paolo Barilla share an 85% stake in the largest company in the world, Forbes reported in 2016. At the time, Forbes estimated that the siblings were worth about $1.5 billion each.

Guido Barilla serves as the Barilla’s chairman, while Luca Barilla and Paolo Barilla are both vice-chairmen.

Jean-Marc Giboux/AP Images for Barilla

Isaac Larian, the CEO of Little Tikes and Bratz dolls maker MGA Entertainment, was also kicked off of Forbes' list.

An heiress to Krispy Kreme-owner JAB Holdings may no longer be a billionaire, but she's still the richest person in New Hampshire, according to Forbes.

Andrea Reimann-Ciardelli, 62, relocated from Germany to Hanover, New Hampshire, Forbes reported. Reimann-Ciardelli inherited a stake in her family’s investment firm JAB Holdings, which she sold to relatives in 2003, according to Forbes. JAB also owns Peet’s Coffee and Panera Bread.

Brandes, 76, built his fortune running Brandes Investment Partners, the San Diego-based investment management firm he founded in 1974. according to Forbes. At its peak, Brandes had over $100 billion under management, but now has only $31 billion, Forbes reported. Brandes left the firm in February 2018.